1. Field of the Invention
The present invention relates to firearms and specifically to a handgrip apparatus for mounting on a forward portion of a firearm, particularly one having a rail such as a Picatinny rail. More particularly, this invention relates to a vertical style handgrip or pistol grip that is adapted to be mounted on the forward portion of a firearm, preferably on a Picatinny rail, that allows for the selective movement of the handgrip not only along the length of the rail, but for different angular orientations of the handgrip to the rail or barrel to comfortably accommodate a left handed or right handed shooter or a shooter with an atypical hand/arm angulation. The handgrip apparatus permits the handgrip to pivot to an ergonomically acceptable position to accommodate the hand and then be locked in such position prior to use.
2. Description of the Related Art
Referring for general background to FIGS. 1 and 2, most hunting firearms share the same basic design. The forearm portion is positioned along the length and below the rifle barrel 132 and the receiver 122 is positioned in an area just forward of the trigger 123. The firearm then transitions to the shoulder stock 125. This basic design is used today on most traditional style hunting rifles. Such known firearms tend to force the shooter's wrists into unnatural positions, which if continued for extended periods of time, becomes very uncomfortable.
Early style handguns had equally uncomfortable handgrip designs. However, the development of the automatic pistol brought about the relatively comfortable vertical style handgrip or pistol grip. The shooter's hand, when raised from his/her side, remains in a vertical or upright position with the thumb on top. While shooting, such a vertical style handgrip maintains the hand and wrist in a natural, untwisted position. Most such vertical style handgrips or pistol grips are symmetrical about a Vertical Plane passing through the handgrip and are angled forward from the bottom or distal portion, i.e., butt, to the top or proximal portion of the handgrip. The hand and wrist follow this naturally, without becoming contorted and uncomfortable. Because it is a natural position, the shooter can keep his/her hand on the handgrip for longer periods of time, without the hand or wrist becoming stressed and/or pained. This ergonomically correct position allows the shooter to use the handgun for extended periods of time while maintaining control.
This vertical style handgrip or pistol grip eventually transitioned to use on rifles for the shooting (trigger operating) hand, and has become almost standard on military type rifles worldwide. Referring to FIG. 1, the handgrip 121 depicts such a handgrip at the rear of the trigger 123.
For simplicity of discussions herein, the distal portion of the handgrip D can be considered the butt part of the handgrip that is held in the shooter's hand and the proximal portion of the handgrip P is the portion of the handgrip that is attached to the main portion of the firearm.
As is well known to firearm enthusiasts, large caliber and other automatic firearms are often difficult to control when firing, with a lack of control often resulting in muzzle rise which can cause the marksman to shoot wildly or above an intended point of aim or target. It is thus important that the firearm be maintained in a steady, stable position by the shooter to ensure accuracy. Thus, firearms were developed that included a fore or forward handgrip, typically permanently mounted in a fixed position under the barrel of the firearm. The most unattractive handgrips are referred to as “broomsticks,” i.e. a simple round tube or modified tube shape mounted perpendicular to the forearm. Such handgrips are useful, but not aesthetically desirable.
The 1921 Thompson submachine gun is an early example of a firearm having fixed in-line front and rear symmetrical vertical style handgrips or pistol grips. However, such a fixed in-line forearm handgrip on this submachine gun is extremely awkward to grasp properly, particularly when a cylindrical drum magazine is attached. Such pistol grips or vertical style handgrips are mounted and locked in one position on the forward portion of a rifle type firearm stock, generally with the Vertical Plane through the handgrip lined up with the Central Axis of the rifle barrel. See for example, FIG. 5 wherein the handgrip 604 is aligned with the center line or Central Axis CA of the firearm. As depicted therein, such “in-line” handgrips are awkward and uncomfortable to grip by the support arm 602 and hand 604 (non-trigger pulling arm and hand) which reach across the chest of the shooter. There are also available handgrips handgrips that include accessory devices, e.g., lasers, rifle supports, that are mounted on the forward portion of a rifle. Such handgrips are also locked in one position, in-line with the Central Axis of the rifle barrel.
In order to overcome the deficiencies associated with a permanently fixed fore handgrip, there has also been developed handgrips which are moveably mounted to the fore end of firearm so as to be capable of movement along a single axis, such axis typically runs beneath the barrel and is parallel to the Central Axis of the barrel of the firearm. Such moveable fore handgrips include a rail mount portion and a handle portion, the rail mount portion being slidably mounted to a rail structure, e.g., Picatinny rail, that is mounted to and extending along the underside of the barrel. With this type structure, typically the rail mount portion has a dove-tailing rail engaging surface preventing the removal of the fore handgrip from the rail. Once such fore handgrip is moved to a desired position upon the corresponding rail, the fore handgrip is typically maintained in such position by the tightening of one or more mechanical fasteners such as set screws which extend through the rail mount portion and into direct engagement with the rail. Such a sliding fore handgrip is capable of sliding only along one axis, i.e., the axis of the rail.
The following is a list of US Published applications and US patents related to this art:                2005/0241206 to Lemire        2006/0191183 to Griffin        2008/0010890 to Vice        2009/0056192 to Oz        2009/0193702 to Lin        2010/0122484 to Moody        2010/0132239 to Moody        2010/0146836 to Moody        U.S. Pat. No. 2,386,802 to Johnson        U.S. Pat. No. 2,826,848 to Davies        U.S. Pat. No. 2,933,843 to McFeeter        U.S. Pat. No. 3,623,257 to Ray        U.S. Pat. No. 6,658,781 to Bowen        U.S. Pat. No. 6,901,691 to Little        U.S. Pat. No. 7,121,034 to Keng        U.S. Pat. No. 7,191,557 to Gablowski        U.S. Pat. No. 7,243,454 to Cahill        U.S. Pat. No. 7,559,167 to Moody        U.S. Pat. No. 7,578,089 to Griffin        U.S. Pat. No. 7,614,174 to Beltz        U.S. Pat. No. 7,665,239 to Moody        U.S. Pat. No. 7,665,241 to Oz        U.S. Pat. No. 7,698,847 to Griffin        U.S. Pat. No. 7,712,241 to Teetzel        U.S. Pat. No. 7,793,454 to Beltz        U.S. Pat. No. 7,900,390 to Moody        U.S. Pat. No. 7,941,960 to Matthews        
The present invention addresses many of the aforementioned deficiencies of known forward mounted handgrips by providing a vertical style handgrip or pistol grip which may be selectively positioned along the length of the barrel or underlying rail and the plane of which is capable of being pivotally positioned at any one of a multiplicity of differing pivot angles relative to the barrel or rail of a firearm to accommodate a wide range of shooter preferences, including left and right handed shooters with varying arm lengths. These, as well as other features and attributes of the present invention will be discussed in more detail below.